CONICAL SYNFIN

Abstract

Conical screw conveyors for bulk mixers are described. The conical screw conveyors comprise a first end and a second end; a screw shaft having a first end opposite a second end; helices extending along and around the screw shaft, the pitch oriented to move bulk material generally from the first end to the second end during screw conveyor operation; and a conical section along the screw shaft, the conical section comprising a first cone projecting around the periphery of the screw shaft, the first cone having a tapered end opposite a wide end. Mixers comprising the conical screw conveyors are also described.

Description

CONICAL WORM CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority of U.S. provisional application 63 / 151,180, filed on February 19, 2021, the full content of which is incorporated herein by reference. FIELD OF INVENTION The invention relates to agricultural machinery and, more specifically, to horizontal augers and bulk mixers comprising a conical auger for use in mixing bulk materials such as feed, compost, animal bedding, fertilizers, etc. BACKGROUND Horizontal mixers are typically used to mix bulk materials, such as agricultural materials, including feed and bedding. Conventional mixers usually include one or more horizontally positioned augers and operate at approximately 0.523599–1.256637 rad / s (5–12 rpm) to mix the bulk material. A significant amount of horsepower is generally required to rotate the augers, as the load to be mixed can be very large, ranging, for example, from 907 to 18,145 kg (2,000 to 40,000 lb). In addition, the amount of time required to sufficiently mix the material can be significant and frustrating for the user, as it can take between 8 and 10 minutes to sufficiently mix a load or more. Horizontally positioned augers can be either belt augers or solid helix augers, which have a helix positioned away from a central auger post. The helices typically have a pitch oriented to draw material from the ends of the mixer toward the center, usually toward a conversion zone or point, which is generally aligned with a gate on the side of the mixer. The operation of a traditional auger in a mixer, such as a horizontal mixer, can cause compression, clumping in the mix, and / or the breakdown, destruction, or reduction of effective fiber in the feed. Dead spaces can also be created in the mixer during mixing. Uneven discharge from the mixer may also be observed. Therefore, there is a need for an auger for use in a mixer, for example, a horizontal mixer, that mitigates any of the disadvantages mentioned above or as observed in the industry. COMPENDIUM In one embodiment, the present invention provides a conical screw conveyor for a bulk mixer, the conical screw conveyor comprising: an endless pole having a first end opposite a second end; ai? Lznn / zznz / E / YiAi propellers that extend along and around the auger post, the pitch is oriented to move bulk material generally from the first end to the second end during auger operation; a conical section along the worm shaft, the conical section comprises a first cone projecting around the periphery of the worm shaft, the first cone having a tapered end opposite a wide end. In another form of the conical screw or conical screws as described above, the screw is a ribbon screw and the helices are ribbon helices. In another form of the tapered worm or tapered worms as described above, the first cone is generally positioned substantially at or near the second end of the worm shaft, the tapered end is oriented towards the first end of the worm shaft and the wide end is oriented towards the second end of the worm shaft. In another embodiment of the conical worm or conical worms as described above, the conical section further comprises a second cone projecting from the worm post comprising a tapered end opposite a wide end and wherein the second cone has an orientation opposite to the first cone and wherein a wide end of the second cone abuts or is adjacent to the wide end of the first cone. In another embodiment of the tapered screw or tapered screws as described above, the helices or ribbon helices comprise a first pitch section comprising a pitch oriented to move bulk material generally from the first end to the second end and a second pitch section located opposite the first pitch section and having an orientation to move bulk material generally from the second end to the first end of the screw, and wherein the position at which the first pitch section meets the second pitch section defines a conversion point, and wherein the tapered section overlaps with the conversion point. In a further embodiment of the tapered screw or screws as described above, the screw or screws further comprise a lining spanning the distance from the ribbon helices to the first and, optionally, the second cone, in the tapered section, thereby forming solid screw helices in the tapered section. In another form of the conical screw or conical screws as described above, the lining is integrated into the helices in the conical section and the conical section comprises solid helices. In another form of the conical screw or screws as described above, the screw or screws further comprise screw vanes mounted on the screw to help unload the mixing chamber. In another form of the conical worm gear or conical worm gears as described above, the first and / or second cone is a round cone or a pyramidal cone with 3 or more sides. In another form of the conical worm or conical worms as described above, the diameter of the wide end of the first or second cone is less than the diameter of the helices. ai? Lznn / zznz / E / YiAi In another type of conical worm gear or conical worm gears as described above, the first cone and / or the second cone generally have a truncated conical shape. In another form of the conical worm gear or conical worm gears as described above, the first cone and the second cone have a different taper angle. In another form of the tapered worm or tapered worms as described above, the taper angle of the first cone is 135° or more, optionally 140° or more, optionally 145° or more, optionally 150° or more, optionally 155° or more, optionally 160° or more, optionally 165° or more, optionally 170° or more, or optionally 175° or more. In a further embodiment of the tapered screw or tapered screws as described above, the pitch of the helices or ribbon helices is at least the same as the diameter of the helices or ribbon helices. In another form of the tapered screw or tapered screws as described above, the pitch of the helices or ribbon helices is approximately 150 percent of the diameter of the helices or ribbon helices. In another embodiment, the present invention provides a bulk mixer for mixing a bulk material, the bulk mixer comprising: a mixing chamber to contain the bulk material to be mixed; an outlet door for expelling mixed bulk material from the mixing chamber; and a conical screw in the mixing chamber, the conical screw as defined in the present description. In another form of the mixer or mixers as described above, the conical screw is as defined in the present description, where the conversion point is generally aligned with or overlaps the outlet in the mixing chamber and the conical section is generally aligned with the outlet door. In another form of mixer or mixer modality as described above, the bulk mixer is a horizontal mixer. In another embodiment, the present invention provides a horizontal mixer for mixing bulk material, the horizontal mixer comprising: a mixing chamber to receive the bulk material to be mixed, the mixing chamber comprises: side walls connected at their lower edges by a channel; a front wall that extends along one front side of the container; a rear wall extending along one rear side of the container; and an outlet door through which the mixed material can be released; one or more lower augers situated longitudinally in the channel, wherein at least one of the one or more lower augers is a tapered auger as defined in the present description; and one or more upper augers situated longitudinally in the mixing vessel substantially above the one or more lower augers, wherein the channel is shaped to receive one or more lower augers, optionally wherein a taper angle of the first taper is 135° or more, optionally 140° or more, optionally 145° or more, optionally 150° or more, optionally 155° or more, optionally 160° or more, optionally 165° or more, optionally 170° or more or optionally 175° or more. In another embodiment of the mixer or mixers as described above, the ribbon propellers or helices comprise a first passage section comprising a passage oriented to move bulk material generally from the front wall towards the outlet door and a second passage section located opposite the first passage section and having an orientation to move bulk material generally from the rear wall towards the outlet door of the screw conveyor, and wherein the position where the first passage section meets the second passage section defines a conversion point, and wherein the conical section overlaps with the conversion point. In another modality of the mixer or mixers as described above, the conversion point is generally aligned with or overlaps the outlet door in the mixing chamber, and the conical section is generally aligned with or overlaps the outlet door. In another embodiment of the mixer or mixers as described above, there are at least two lower augers and the at least two lower augers are conical augers, each independently as defined herein, the at least two lower augers are defined as a lower auger on the outlet door side located on the mixing chamber side comprising the outlet door and a lower auger on the non-outlet door side located on the mixing chamber side not comprising the outlet door. In another embodiment of the mixer or mixers as described above, the lower auger on the outlet door side has its conical section positioned to overlap with the outlet door. In another embodiment of the mixer or mixers as described above, the wide end of the first or second cone of the lower auger on the outlet door side has a smaller diameter than the wide end of the first or second cone of the lower auger on the non-outlet door side. In another form of the mixer or mixers as described above, the wide end of the first or second cone of the lower auger on the outlet door side has a larger diameter than the wide end of the first or second cone of the lower auger on the side without the outlet door. In an additional embodiment of the mixer or mixers as described above, the conical section of the lower auger on the side without an outlet door is not aligned with the conical section of the lower auger on the side with the outlet door. In an additional embodiment of the mixer or mixers as described above, the conical section of the lower auger on the side without the outlet door is aligned with the conical section of the lower auger on the side with the outlet door. In an additional embodiment of the mixer or mixers as described above, the conical section of the lower auger on the side without an outlet door overlaps with the conical section of the lower auger on the side with the outlet door. ai? Lznn / zznz / E / YiAi In an additional embodiment of the mixer or mixers as described above, the conical section of the lower auger on the outlet door side comprises a first and / or second cone having a different taper angle than a first and / or second cone of the lower auger on the non-outlet door side. In an additional embodiment of the mixer or mixers as described above, one or more upper augers are a ribbon auger. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top schematic view illustrating one embodiment of a tapered ribbon screw according to one embodiment of the invention; Figure 2 is an symmetrical view of the tapered ribbon screw shown in Figure 1; Figure 3 is a top schematic view illustrating another embodiment of a tapered ribbon screw according to an embodiment of the invention; Figure 4 is an isometric view of the tapered ribbon screw shown in Figure 3; Figure 5 is a top schematic view illustrating another embodiment of a tapered ribbon screw according to an embodiment of the invention; Figure 6 is an isometric view of the tapered ribbon screw shown in Figure 5; Figure 7 is a top schematic view illustrating another embodiment of a tapered ribbon screw according to an embodiment of the invention; Figure 8 is an isometric view of the tapered ribbon screw shown in Figure 7; Figure 9A is an illustrative isometric view of a modality of a bulk mixer comprising a modality of a conical ribbon screw according to the invention; Figure 9B is a top schematic view illustrating the bulk mixer and tapered ribbon screw as shown in Figure 9A; Figure 9C is an illustrative end view of the bulk mixer and tapered ribbon screw as shown in Figure 9A; Figure 10 is an illustrative top view of another embodiment of a bulk mixer comprising another embodiment of a conical ribbon screw according to the invention; and Figure 11 is an illustrative top view of another embodiment of a bulk mixer comprising another embodiment of a conical ribbon screw according to the invention. DETAILED DESCRIPTION This description outlines examples and embodiments of conical screw conveyors and horizontal mixers comprising conical screw conveyors, including apparatus, systems for these, and methods and processes for using them, for mixing bulk material, such as agricultural material, for example, feed, compost, or bedding. It should be noted that the embodiments and examples provided herein are for illustrative purposes intended for those skilled in the art and are not intended to be limiting in any way. All references to embodiments or examples throughout this description should be regarded as illustrative and non-limiting. It should be noted that none of the features described herein are intended to be essential unless specifically stated as such.Reference to any dimension or measurement is for illustrative purposes and is not intended to be limiting and is not meant to be an exact and limiting measure, and the term approximately is intended to apply to all such dimensions and measurements and at least accounts for the inaccuracies and errors associated with taking such measurements and the devices for taking them. This document describes an auger with a tapered cross-section that helps to more effectively mix bulk material in a bulk mixer. It has been determined that adding a tapered cross-section to an auger, such as a ribbon auger or a solid auger, can enable the auger to mix bulk material more effectively when used in a mixer, for example, a horizontal mixer. The use of a tapered auger can potentially reduce mixing times and / or the energy required to mix bulk material, reduce lump formation and / or compression of the mixing material, reduce dead spots in the mix, and / or reduce damage to the effective fiber in a feed mix. A conical auger according to the present invention can be used in a bulk mixer, such as a bulk agricultural mixer or a bulk feed mixer, and can be used in a horizontal bulk mixer, such as a horizontal agricultural mixer or a horizontal feed mixer. An example of a horizontal mixer suitable for use with a conical auger is shown in Canadian patent application 3,034,724, filed on February 22, 2019, entitled "Horizontal Mixer With Stacked Augers," which is incorporated herein by reference in its entirety. An example of a tapered belt screw according to one aspect of the present invention is a tapered belt screw generally shown in Figures 1 and 2. The tapered belt screw includes a screw post along which the belt helices run. The belt helices have a pitch oriented to draw material from a first end of the screw to an opposite second end of the screw. Alternatively, the belt screw may have a pitch oriented to draw material from a second end of the screw to a first end. The screw shown in Figures 1 and 2 includes helices having a first pitch section oriented to draw material from the first end of the screw to the second end and a second pitch section. 140 oriented to take material from the second end of the screw conveyor 100 to the first end of the screw conveyor 100.This can also be called forward helical flight and reverse helical flight. The point where the first pitch section 145 and the second pitch section 140 meet is called the conversion point 135. When the screw 100 is located in a mixer, the pitch is oriented to draw material from one end wall of the mixing chamber. When the screw 100 has two pitch sections 140 and 145, the screw's operation draws material from each end of the mixer's mixing chamber. The conversion point 135 can be located so that it is aligned with or overlaps an outlet door in the mixing chamber. This is especially useful if a single auger is used, or if a single lower auger is used in a stacked auger configuration, or if multiple augers are used and the auger on the exit gate side has a conversion point that overlaps with or is aligned with the exit gate.This is explained in more detail with reference to Figures 9A to 11. The tapered belt screw 100 also includes a tapered section 120 consisting of a first taper 110 and optionally a second taper 115. Each taper has a tapered end opposite a wide end. As shown in Figures 1 and 2, the first taper 110 is oriented opposite the second taper 115, and their wide ends either abut or are adjacent. Typically, the tapered section 120 overlaps with the conversion point 135. In one embodiment, the conversion point 135 is located where the first taper 110 and the second taper 115 abut each other. The conical section 120 may have cones whose diameter at their wide end is no greater than the external diameter of the helices 105, also called the worm diameter. In tapered section 120, the ribbon helices 105 may include a liner 130 spanning the space between the cone 110 or 115 and the ribbon helices, resulting in solid helices in tapered section 120. The liner 130 prevents material from wrapping around the cone 110 and / or 115 and becoming lodged between the cones and the helices 105 during the operation of the screw conveyor 100. During the manufacture of the screw conveyor 100, tapered section 120 may be added to the screw shaft 125, and then the helices may be added. Solid helices may be added around tapered section 120, and ribbon helices may be added along all or substantially all of the remaining screw shaft. The liner 130 may be integrated directly into the helices of tapered section 120. It has been observed that using a conical auger, as shown with reference to Figures 1 and 2, can result in mixing bulk material in a horizontal auger in a significantly shorter time while using the same amount of energy to drive the mixer. A user can also reduce the amount of energy used and still achieve a reduced mixing time, or a similar mixing time if the energy is reduced even further. This can lead to a reduction in energy consumption, fuel consumption, and carbon emissions. Furthermore, it has been observed that the conical auger appears to push the feed out of the discharge gate in a horizontal mixer more smoothly and quickly. The conical auger seems to mix the bulk material without compressing it as much as a traditional solid auger or a traditional belt auger, and the mixed feed exits the gate in a much better condition with less damage to the effective fiber. For example, when using steamed corn, it has been observed that a mixer using a traditional belt conveyor crumples it, creating compressed crumbs that reduce the effective fiber content. It is preferable to avoid or minimize the breakdown or destruction of the effective fiber. As can be seen in the conical section 120 of Figures 1 and 2, the first cone 110 and the second cone 115 can have different lengths, resulting in a different taper angle between cones 110 and 115. The taper angle is the angle formed by the worm shaft 125 and either cone 110 or 115. Figure 3 shows an example of the taper angle, where the second cone 115 has a taper angle of 163°. An optional taper angle of 135° or greater appears to be ideal, but any suitable taper angle can be adopted. It will be appreciated that the first and second cones 110 and 115 can have similar dimensions or they can be different. One cone can be longer than the other and have a different taper angle. Alternatively, the first cone 110 may have a larger or smaller diameter at the wide end than the second cone 115.Cones of different sizes and shapes can also be used, and all cones are considered by the inventors and are within the scope of the invention. Generally, the cones can have a truncated conical shape. The outer surface or cover of the cones may have a smooth, rounded shape around its circumference and be made of a single section or multiple sections joined together, for example, by welding. The piece or pieces may be stamped to obtain the desired shape. The outer surface or cover may consist of a plurality of flat surfaces that meet at an angle to form a pyramidal shape with multiple faces. Each face may be a separate piece joined together or may be formed by stamping, pressing, or a combination of these or other suitable techniques. Any suitable inner frame may be used to support the outer surface or cover. For example, one or more inner plates may be mounted on the auger post 105 to support the surface or cover so that the weight of the load to be mixed does not crush the cone. For example, as shown with reference to Figure 3, a series of 335 plates is used to support the cone surface or cover on the auger post 325. The 335 plates may be made of any suitable strong material, for example, steel or stainless steel. Furthermore, although five plates are shown being used to support the 310 and 315 cones in Figure 3, any suitable number or orientation of support plates may be used, and any suitable support structure may be implemented as required. The pitch of the 105 belt screw can vary, and it will be appreciated that any suitable pitch on the 105 belt screw can be used to mix bulk material as intended. The pitch can be very shallow or it can be 100% or greater. The pitch is generally expressed as a length and can be expressed as a ratio compared to the diameter of the belt screw. It has been observed that having a pitch of at least a 1:1 pitch-to-screw diameter ratio, also expressed for the purposes of this description as a pitch of at least 100%, tends to mix bulk material well. The pitch can be greater than 1:1 or greater than 100%. For example, the pitch in the first section of pitch 145, where the diameter of the 105 belt screw is 71.12 cm (28 in) and the pitch is 91.44 cm (36 in), is approximately 129%. The pitch of the 305 belt propellers of the 300 auger shown with reference to Figure 3 is 121.92 cm (48 inches), or 48:42 or 114%.The pitch ratio can be as large as 3:2 or 150%, or even larger. It is understood that the pitch can be any suitable ratio that allows for the production of a usable mix by the operation of the conical screw in a mixer. It is also understood that the pitch ratio in the first section (pitch 145) can be different from or the same as the pitch ratio in the second section (pitch 140). It will be appreciated that the 100 screw conveyor can be manufactured from any suitable material or combination of materials, and the material is not intended to be limiting in any way. The 100 screw conveyor and its components can be manufactured from steel or stainless steel and can be welded, stamped, cut, or manufactured using press breaking or a die, or a combination thereof. Figures 3 and 4 show another embodiment of a tapered screw conveyor 300 for use in a bulk mixer. The tapered screw conveyor 300 is generally similar to that shown with reference to Figures 1 and 2 in that the tapered screw conveyor 300 comprises a screw post 325 along which the ribbon helices 305 run. The ribbon helices 305 have a pitch oriented to move the material away from each end and toward a conversion point 340 where the opposing pitches meet. The tapered worm gear 300 comprises a tapered section 320 which includes a first cone 310 adjacent to and oriented opposite a second cone 315. In the embodiment shown with reference to Figures 3 and 4, the first cone 310 and the second cone 315 generally have the same dimensions, unlike the first and second cones of the worm gear 100 which had different lengths and different taper angles.Furthermore, the tapered section 320 of the tapered worm 300 is positioned slightly inward of the end of the worm shaft 325, where the tapered section 120 of the tapered worm 100 was typically at the end of the worm shaft 125. This illustrates that the tapered section 320 can be located at any suitable point along the worm shaft 325 and overlap with the conversion point 340. The tapered section 320 also includes the lining 330, which spans the space between the cone 310 or 315 and the ribbon helices 305, resulting in solid helices in the tapered section 320. Figures 5 and 6 show another embodiment of a tapered screw conveyor 500 comprising a tapered section 520 that includes only a first cone 510. The tapered screw conveyor 500 includes a screw post 525 along which the ribbon helices 505 run. The ribbon helices 505 have a pitch oriented to draw material from one end to the other end of the screw conveyor 500. The screw conveyor 500 has only a first pitch and does not include a pitch designed to draw material from the other end of the screw conveyor 500. As a result, the tapered section 510 is positioned at the end of the screw conveyor 500 and includes only a single cone 510. There is no conversion point in the helices 505 since there is no oppositely oriented pitch in the helices. This illustrates that the tapered section 520 can include only a single cone 510.It will be noted that the conical section can be positioned at the end of the auger 500, but it is also contemplated that the single cone 510 can be positioned away from the end of the auger 500 towards the center, and the auger helices 505 can include a first and a second pitch oriented to extract material from each side, and that the single cone 510 can be positioned at the conversion point of the two pitches. The conical section 520 also includes the liner 530, which spans the space between the cone 510 and the ribbon helices 505, resulting in solid helices in the conical section 520. The cone 510 includes a support structure composed of a series of plates 535, which are used to support the cone surface or cover on the auger post 525. The plates 535 can be made of any suitable strong material, for example, steel or stainless steel.Furthermore, although three plates used to support the 510 cone are shown in Figure 5, any suitable number or orientation of support plates can be used, and any suitable support structure can be implemented as required. Figures 7 and 8 show another embodiment of a tapered screw conveyor 700 similar to that shown with reference to Figures 3 and 4. The tapered screw conveyor 700 comprises a screw post 725 along which the ribbon helices 705 run. The ribbon helices 705 have a pitch oriented to move the material away from each end and towards a conversion point 740 where the opposite pitches meet. The tapered worm gear 700 comprises a tapered section 720 that includes a first cone 710 adjacent to and oriented opposite a second cone 715. In the embodiment shown with reference to Figures 7 and 8, the first cone 710 and the second cone 715 generally have the same dimensions, unlike the first and second cones of the worm gear 100, which had different lengths and different taper angles.Furthermore, the tapered section 720 of the tapered screw 700 is generally positioned in the center of the screw post 725, where the tapered section 120 of the tapered screw 100 was generally at the end of the screw post 125. This further illustrates that the tapered section 720 can be located at any suitable point along the screw post 725 and overlap with the conversion point 740. The tapered section 720 also includes the lining 730, which spans the space between the cone 710 or 715 and the ribbon helices 705, resulting in solid helices in the tapered section 720. The cones 710 and 715 include a support structure consisting of a series of plates 735, which are used to support the cone surface or cover on the screw post 725. The plates 735 can be made of any suitable strong material. For example, steel or stainless steel.Furthermore, although five plates used to support cones 710 and 715 are shown in Figure 7, any suitable number or orientation of support plates may be used, and any suitable support structure may be implemented as required. It will be appreciated that although a tapered ribbon screw has been exemplified and illustrated with reference to Figures 1 to 8, it is within the contemplated invention that the screw can be a solid screw with a tapered section and the invention is not limited to ribbon screws with a tapered section. Figures 9A, 9B, and 9C show a mixer 900 for mixing bulk material. The mixer 900 has an open top into which bulk material, such as bulk agricultural material, can be placed for mixing. The mixing bowl is defined by side walls 930 and 935, which are connected at their lower ends by a channel 960. A front wall 950 and a rear wall 920 span each end of the mixing bowl, thus forming the open-top mixing bowl, also called the mixing chamber. The horizontal mixer 900 shown in Figures 9A-9C is a horizontal mixer with a quadruple auger arrangement, including two sets of stacked augers, as can be seen more clearly in the top view of Figure 9B and the end view of Figure 9C. The mixer 900 includes lower tapered ribbon augers 910, which are positioned longitudinally in the mixing vessel. The channel 960 is W-shaped to receive the double lower tapered ribbon augers 910, such that each lower tapered ribbon auger is at least partially enclosed or recessed within its own channel. As can be seen in Figure 9C, the W-shaped channel 960 consists of two parallel channels, each adapted to receive its own auger and can be of different sizes depending, for example, on the diameter of the auger to be received. For instance, each lower conical ribbon auger can have a different diameter and can be positioned at a different height. It will be appreciated that any suitable auger configuration can be used and that the ribbon and / or conical solid augers of the present invention, as defined herein, can be adapted to receive a mixer, or the mixer can be adapted to receive a ribbon and / or conical solid auger as defined herein.The description of the horizontal mixer with reference to Figures 9A-9C is only an example of a mixer that may use a conical screw or a conical ribbon screw of the present invention and is for illustrative purposes and it is not the intention of the inventors that only horizontal mixers such as the one shown in Figures 9A-9C or 10 and 11 may be used in conjunction with the conical ribbon screws of the invention. As can be seen in Figures 9A-9C, the lower augers of the horizontal mixer are tapered ribbon augers 910. The upper augers 940 can be ribbon augers or solid augers. They can also be tapered augers. The mixer 900 comprises an outlet door 970 located in any suitable position to allow the discharge of the mixed material from the mixing chamber. In one embodiment, the outlet door 970 may be in the side wall 935 of the mixer 900 and may be on the driver's side of the mixer 900, allowing a user operating the vehicle towing the mixer to more easily see the outlet door 970 in the rearview mirror and exit the cab of the vehicle towing the mixer more efficiently to access the outlet door 970. As described above, the tapered belt screw on the exit door side 911 has the tapered section 990 aligned with or overlapping the exit door 970. The tapered belt screw on the non-exit door side 912 has the tapered section 980 located at any suitable point along the screw post 921. The pitch of the lower augers 910 can be oriented to draw material from the front wall 950 and the rear wall 920 into the center of the mixing chamber. The conversion point of each of the lower augers 910 can be the same or different, as shown in Figures 9A to 9C. In the mixer 900 shown with reference to Figures 9A-9C, the lower augers 910 can be any suitable ribbon auger or tapered solid as described herein or as contemplated by the inventors. The lower augers 910 shown in Figures 9A-9C are ribbon augers as described with reference to Figures 1-2 (lower ribbon auger 911) and Figures 3-4 (lower ribbon auger 912). The lower augers 911 and 912 have different diameters, but it is contemplated that the lower augers may have the same diameter and optionally may have the same positioning of the tapered section. Figures 10 and 11 show mixers that have two other configurations for the lower conical ribbon augers. Figure 10 shows a horizontal mixer 1000 comprising lower tapered ribbon augers, including a tapered ribbon auger 1011 on the outlet door side and a tapered ribbon auger 1012 on the non-outlet door side. The tapered ribbon auger 1011 has a tapered section 1090 that overlaps with the outlet door 1070 in the mixer 1000. The tapered ribbon auger 1012 has a tapered section 1080 positioned along the auger post at a point that does not overlap with the tapered section 1090. Lznn / zznz / E / YiAi of the conical belt screw 1011. The pitch of the lower screws 1011 and 1012 can be oriented to draw material from the front wall 1050 and the rear wall 1020 into the center of the mixing chamber. The upper screws 1040 can be belt screws or solid screws. They can also be conical belt screws. Figure 11 shows a horizontal mixer 1100 comprising lower tapered ribbon augers, including a tapered ribbon auger 1111 on the outlet door side and a tapered ribbon auger 1112 on the non-outlet door side. The tapered ribbon auger 1111 has a tapered section 1190 that overlaps with the outlet door 1170 in the mixer 1100. The tapered ribbon auger 1112 has a tapered section 1180 positioned at a front end of the auger post at a point adjacent to the front end of the mixing chamber 1150. The tapered section 1180 comprises a single cone as described with reference to Figures 5-6. The pitch of the lower auger 1111 can be oriented to draw material from the rear wall 1120 and the front wall 1150 toward the center of the mixing chamber.The pitch of the conical belt screw 1112 is oriented to extract material in one direction only, in this case from the rear of the mixer 1120 to the front 1150. The upper screws 1140 can be belt screws or solid screws. They can also be conical belt screws. The conical belt augers on the exit door side and the conical belt augers on the non-exit door side described herein may have first and second cones with identical or non-identical diameters. In embodiments with non-identical diameters, the diameter of the wide ends of the first or second cone of the conical belt auger on the exit door side may be smaller than the diameter of the wide end of the first or second cone of the conical belt auger on the non-exit door side. In other embodiments, the diameter of the wide ends of the first or second cone of the conical belt auger on the exit door side may be larger than the diameter of the wide end of the first or second cone of the conical belt auger on the non-exit door side. It will be appreciated that any suitable horizontal mixer with any suitable auger configuration and orientation and any suitable number of augers can be used. The mixer may comprise a tapered ribbon auger, such as one defined herein or contemplated by the inventors, and the tapered section may be overlapped with or aligned with the mixer's outlet door. It will be noted that the conical auger as described herein can be used in conjunction with paddles mounted on the auger. The paddles can be mounted in any suitable shape and / or position. The paddles can be used to assist in mixing and / or discharging the bulk material. One or more illustrative embodiments have been described by way of example. Those skilled in the art will understand that numerous variations and modifications can be made without departing from the scope and spirit of the invention as defined herein and in the claims. Such modifications and variations are within the intended scope of the invention and the inventors' vision.

Claims

1. A tapered screw for a bulk mixer, the tapered screw comprises: a screw post having a first end opposite a second end; helices extending along and around the screw post, the pitch being oriented to move bulk material generally from the first end to the second end during screw operation; a tapered section along the screw post, the tapered section comprising a first cone projecting around the periphery of the screw post, the first cone having a tapered end opposite a wide end.

2. The tapered screw of claim 1, wherein the screw is a ribbon screw and the helices are ribbon helices.

3. The tapered auger of claim 1 or 2, wherein the first cone is generally positioned substantially at or near the second end of the auger post, the tapered end is oriented towards the first end of the auger post and the wide end is oriented towards the second end of the auger post.

4. The tapered screw of claim 1 or 2, wherein the tapered section further comprises a second cone projecting from the screw post comprising a tapered end opposite a wide end and wherein the second cone has an orientation opposite to the first cone and wherein a wide end of the second cone abuts or is adjacent to the wide end of the first cone.

5. The tapered screw of any one of the preceding claims, wherein the helices or ribbon helices comprise a first pitch section comprising a pitch oriented to move bulk material generally from the first end to the second end and a second pitch section located opposite the first pitch section and having an orientation to move bulk material generally from the second end to the first end of the screw, and wherein the position at which the first pitch section meets the second pitch section defines a conversion point, and wherein the tapered section overlaps with the conversion point.

6. The tapered screw of any one of claims 2 to 5, further comprising a lining spanning the distance from the ribbon helices to the first and, optionally, the second cone, in the tapered section, thereby forming solid screw helices in the tapered section.

7. The tapered screw of claim 6, wherein the lining is integrated into the helices in the tapered section and the tapered section comprises solid helices.

8. The conical auger of claim 1 or 2, further comprising auger vanes mounted on the auger to assist in unloading the mixing chamber.

9. The tapered worm gear of any one of the preceding claims, wherein the first and / or second cone is a round cone or a pyramidal cone with 3 or more sides. ai? Lznn / zznz / E / YiAi 10. The tapered worm gear of any one of the preceding claims, wherein the diameter of the wide end of the first or second cone is less than the diameter of the helices.

11. The conical worm gear of any one of the preceding claims, wherein the first cone and / or the second cone have a generally truncated conical shape.

12. The tapered worm gear of any one of claims 4 to 11, wherein the first cone and the second cone have different taper angles.

13. The tapered worm of any one of the preceding claims, wherein a taper angle of the first cone is 135° or more, optionally 140° or more, optionally 145° or more, optionally 150° or more, optionally 155° or more, optionally 160° or more, optionally 165° or more, optionally 170° or more or optionally 175° or more.

14. The tapered screw of any one of the preceding claims, wherein the pitch of the helices or ribbon helices is at least the same as the diameter of the helices or ribbon helices.

15. The tapered screw of any one of the preceding claims, wherein the pitch of the helices or ribbon helices is approximately 150 percent of the diameter of the helices or ribbon helices.

16. A bulk mixer for mixing a bulk material, the bulk mixer comprising: a mixing chamber for containing the bulk material to be mixed; an outlet door for expelling mixed bulk material from the mixing chamber; and a tapered screw in the mixing chamber, the tapered screw as defined in any one of claims 1 to 15.

17. The bulk mixer of claim 16, wherein the conical screw is as defined in any one of claims 5 to 15, wherein the conversion point is generally aligned with or overlaps the outlet in the mixing chamber and the conical section is generally aligned with the outlet gate.

18. The bulk mixer of claim 16 or 17, wherein the bulk mixer is a horizontal mixer.

19. A horizontal mixer for mixing bulk material, the horizontal mixer comprising: a mixing chamber for receiving the bulk material to be mixed, the mixing chamber comprising: side walls connected at their lower edges by a channel; a front wall extending along a front side of the container; a rear wall extending along a rear side of the container; and an outlet door through which the mixed material can exit; one or more lower augers situated longitudinally in the channel, wherein at least one of the one or more lower augers is a tapered auger as defined in any one of claims 1 to 14; and one or more upper augers situated longitudinally in the mixing container substantially above the one or more lower augers, wherein the channel is shaped to receive one or more lower augers.

20. The horizontal mixer of claim 19, wherein the helices or ribbon helices comprise a first passage section comprising a passage oriented to move bulk material generally from the front wall towards the outlet door and a second passage section located opposite the first passage section and having an orientation to move bulk material generally from the rear wall towards the outlet door of the screw conveyor, and wherein the position where the first passage section meets the second passage section defines a conversion point, and wherein the conical section overlaps with the conversion point.

21. The horizontal mixer of claim 20, wherein the conversion point is generally aligned with or overlaps the outlet door in the mixing chamber and the conical section is generally aligned with or overlaps the outlet door.

22. The horizontal mixer of any one of claims 19 to 21, wherein there are at least two lower augers and the at least two lower augers are tapered augers, each independently as defined in any one of claims 1 to 15, the at least two lower augers being defined as an outlet-side lower auger located on the mixing chamber side comprising the outlet door and a non-outlet-side lower auger located on the mixing chamber side not comprising the outlet door.

23. The horizontal mixer of claim 22, wherein the lower screw on the outlet door side has the conical section positioned to overlap with the outlet door.

24. The horizontal mixer of claim 22 or 23, wherein the wide end of the first or second cone of the lower auger on the outlet door side has a smaller diameter than the wide end of the first or second cone of the lower auger on the non-outlet door side.

25. The horizontal mixer of claim 22 or 23, wherein the wide end of the first or second cone of the lower auger on the outlet door side has a larger diameter than the wide end of the first or second cone of the lower auger on the non-outlet door side.

26. The horizontal mixer of any one of claims 22 to 25, wherein the conical section of the lower auger on the side without the outlet door is not aligned with the conical section of the lower auger on the side with the outlet door.

27. The horizontal mixer of any one of claims 22 to 25, wherein the conical section of the lower auger on the side without the outlet door is aligned with the conical section of the lower auger on the side with the outlet door.

28. The horizontal mixer of any one of claims 22 to 25, wherein the conical section of the lower auger on the side without the outlet door overlaps with the conical section of the lower auger on the side with the outlet door.

29. The horizontal mixer of any one of claims 22 to 28, wherein the conical section of the lower auger on the outlet door side comprises a first and / or second cone having a taper angle different from that of a first and / or second cone of the lower auger on the non-outlet door side.

30. The horizontal mixer of any one of claims 19 to 29, wherein one or more upper augers are a ribbon auger.

31. The horizontal mixer of any one of claims 19 to 30, wherein a taper angle of the first cone is 135° or more, optionally 140° or more, optionally 145° or more, optionally 150° or more, optionally 155° or more, optionally 160° or more, optionally 165° or more, optionally 170° or more or optionally 175° or more.

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